TB 9-4931-537-35
8. Equipment to be
Cross-Checked
a. Standards requiring periodic cross-checks are: Calibrator, John Fluke, Model
5700A/( ); Amplifier, John Fluke, Model 5725A/( ); and Multimeter, Hewlett Packard,
Model 3458A/( ). These standards are also listed at the top of table 1. Additionally, the
organizational chief is responsible for maintaining and assuring all calibration standards
and equipment are in proper calibration and operating condition. Therefore, the chief
may cross-check additional standards deemed necessary.
b. If an organization does not possess specific items of equipment, listed in a above,
the most accurate dc voltage, ac voltage, and resistance standards which receive support
by a higher level calibration activity, will be cross-checked.
c. When
equivalent standards are
used in lieu of
those listed in
table 1, the
organizational chief will develop a cross-check similar to the one specified for the
standard being replaced. This locally developed cross-check will be included in the
cross-check record files.
a. The
ranges and
parameters listed in
table 1 have
been determined to be
adequate
to provide a reasonable check of the standards while at the same time causing a
minimum loss of productive calibration/repair time. The limits assigned are the square
root of the sum of the squares. The tolerances used for each standard were obtained
from the technical bulletin for the standard.
b.
Table 1 has sufficient space for five
consecutive cross-checks. Enter data
legibly,
in blue or black ink, and show all significant digits of the required reading.
c. If a specific standard fails a cross-check, the organizational chief will determine
the action to be taken and document the decision. The action taken must ensure that all
TMDE calibrated with the failed standard are operating in accordance with the
approved calibration procedure. When re-calibration of the TMDE is the course of
action, the TMDE owner will be notified and will determine whether or not re-
calibration is actually necessary (based on usage of the instrument). If re-calibration is
necessary, a mutually agreeable schedule will be established to recalibrate the affected
TMDE.
d. Documentation of corrective actions taken will be recorded when a standard fails
a cross-check. Documentation may be in the form of notations and explanations in the
cross-check table, where possible, or on separate pages attached to the table.
Documentation must be in sufficient detail so that an audit trail can confirm that no
TMDE had been adversely affected.